In the past decades, periodontal regenerative treatment has been an effective and successful treatment modality for deep intrabony defects around periodontally compromised teeth [1]. A recent systematic review and meta-analysis showed that most periodontal regenerative treatment modalities are more effective than open flap debridement (OFD) alone; however, there is still a lack of clear evidence for differences in clinical outcomes between various regenerative therapies [2]. In addition, achieving predictable and sufficient periodontal regeneration with new cementum, periodontal ligament, and alveolar bone formation is still challenging [3].

Gingival recession (REC) associated with periodontitis causes anatomical consequences of the apical spread of plaque, and inevitably, progression of alveolar bone loss [4]. In particular, in the maxillary anterior region, REC accompanied by alveolar bone loss poses esthetic and functional clinical challenges. Numerous root coverage procedures have been proposed to treat REC; and pedicle flaps, free soft tissue grafts, and subepithelial connective tissue grafts can be used alone or in combination [5]. A coronally advanced flap (CAF) with connective tissue graft (CTG) is more effective in achieving complete or partial root coverage than CAF alone [6-8].

Reconstruction of function and esthetics is an important factor in terms of deep intrabony defects and REC in the maxillary anterior region [6]. This case report describes a 3-year follow-up investigation of two patients with deep intrabony defects and REC in the maxillary canine treated using combined periodontal regenerative treatment with CTG.

This case report pertains to two patients who visited the Department of Periodontology, Daejeon Dental Hospital, Wonkwang University College of Dentistry. The patients were healthy with well-controlled systemic diseases for surgical intervention. After regenerative periodontal surgery with CTG, further 3-year follow-up examinations were conducted. The study was approved by the local Institutional Review Board of Daejeon Dental Hospital, Wonkwang University (approval no. W2106/003-001).

Case 1

A 55-year-old male patient visited the Department of Periodontology with discomfort in the left anterior maxilla with gingival swelling, bleeding, and pus discharge. The patient had multiple RECs (>4.5 mm) and showed suppuration with a deep clinical attachment level (CAL, >11.5 mm) around the maxillary left canine (Fig. 1A). On the periapical radiograph, severe vertical bone loss was observed on the mesial side of the canine (Fig. 1B).

Fig. 1. Initial intraoral (A) clinical photograph and (B) periapical radiograph of case 1 patient.

The patient was administered antibiotic (netilmicin 50 mg/mL) and analgesic (diclofenac 90 mg/2 mL) injections 30 min before periodontal regenerative treatment with CTG, and was provided with the following postoperative medications and mouthwash to be used after surgery: antibiotics (amoxicillin 500 mg TID for 5 days), analgesics (ibuprofen 200 mg TID for 5 days), and antimicrobial rinse (chlorhexidine gluconate 0.12%, BID for 2 weeks).

Local anesthetics (2% lidocaine HCl with 1:100,000 epinephrine, Yuan, Seoul, South Korea) were injected at the surgical site. Papilla preservation incisions without vertical releasing incisions were placed on the maxillary left anterior and premolar areas using #12, 15, 15c blades, and an Orban knife (Hu-Friedy, Chicago, IL, USA). After incision and full-thickness flap elevation, the mesial side of the canine showed a deep intrabony defect (Fig. 2A). Subepithelial connective tissue (16 mm × 5 mm) was obtained from the left palatal area using a #15 blade (Fig. 2B).

Fig. 2. (A) After full-thickness flap elevation without vertical releasing incisions on the maxillary buccal side, the canine root is exposed and deep intrabony defect is observed; (B) subepithelial connective tissue after de-epithelization; (C) defect is filled using a mixture of bone grafting material and enamel matrix derivative; (D) subepithelial connective tissue is placed and sutured; (E) flap is coronally positioned and sutured using interrupted and sling sutures; and (F) postoperative periapical radiograph.

Granulation tissue in the intrabony defect and deposition of hard calculus around the tooth were carefully and gently removed using manual curettes (Standard and mini Gracey curettes; Hu-Friedy) and an ultrasonic device (SONICflex air scaler; KaVo, Biberach, Germany). Root conditioning and decontamination were performed using tetracycline-soaked cotton balls (concentration of 50 mg/mL, 2 minutes). The bone defect was filled with a mixture of bone grafting material (demineralized porcine bone matrix, Graft 0.25 g; Purgo Biologics, Seongnam, Korea) and enamel matrix derivate (EMD, Emdogain 0.3 mL; Straumann, Basel, Switzerland) (Fig. 2C). Next, subepithelial connective tissue was placed and sutured on the canine buccal side using 6-0 polygalactin (Vicryl; Johnson & Johnson, New Brunswick, NJ, USA) (Fig. 2D). The surgical site was sutured with 4-0 e-PTFE (Biotex; Purgo Biologics) using interrupted and sling sutures (Fig. 2E, F). The canine remained clinically and radiologically stable over 3 years of follow-up (Fig. 3).

Fig. 3. Canine showed clinically and radiologically stable for (A and B) 1 years, (C and D) 2 years, and (E and F) 3 years follow-up.

Case 2

A 49-year-old male visited the Department of Periodontology with pain in the left anterior maxillary canine along with gingival swelling, bleeding, and moderate-to-severe tooth mobility. The patient had a severe REC (>7 mm) and showed deep CAL (>11 mm) around the maxillary left canine (Fig. 4A). On a periapical radiograph, severe vertical bone loss was observed in the distal part of the canine (Fig. 4B).

Fig. 4. Initial intraoral (A) clinical photograph and (B) periapical radiograph of case 2 patient.

The patient was administered antibiotic (netilmicin 50 mg/mL) and analgesic (diclofenac 90 mg/2 mL) injections 30 minutes before surgery and provided with the following postoperative medications and mouthwash to be used after surgery: antibiotics (amoxicillin 500 mg TID for 5 days), analgesics (ibuprofen 200 mg TID for 5 days), and antimicrobial rinse (chlorhexidine gluconate 0.12%, BID for 2 weeks). After local anesthesia (2% lidocaine HCL with 1:100,000 epinephrine, Yuan, Seoul, South Korea), intra-sulcular incision on #23 and vertical incision on the mesial and distal sides of #23 were placed using #12, 15, 15c blades, and an Orban knife (Hu-Friedy) (Fig. 5A). After incision and flap elevation, the distal side of the canine site showed a deep intrabony defect (Fig. 5B).

Fig. 5. (A) After full-thickness flap elevation with vertical releasing incisions on the maxillary buccal side, (B) the canine root is exposed and deep intrabony defect is observed, (C) subepithelial connective tissue after de-epithelization, (D, E) defect is filled using a mixture of bone grafting material and enamel matrix derivative, (F) flap is coronally positioned and sutured using interrupted and sling sutures, and (G) postoperative periapical radiograph.

Heavy calculus and granulation tissue were carefully removed using curettes (Standard and mini Gracey curettes; Hu-Friedy) and an ultrasonic device (SONICflex air scaler; KaVo). The exposed root surface and intrabony defect were decontaminated with tetracycline-soaked cotton balls (concentration of 50 mg/mL) for 2 minutes. Subsequently, the intrabony defect was filled with a mixture of bone grafting material (demineralized porcine bone matrix, Graft 0.25 g; Purgo Biologics) and EMD (Emdogain 0.3 mL; Straumann). Subepithelial connective tissue (12 mm × 4 mm) was placed using 6-0 polygalactin (Vicryl; Johnson & Johnson). The flap was coronally advanced and sutured with 4-0 e-PTFE (Biotex; Purgo Biologics) using interrupted and sling sutures (Fig. 5C–G). The canine was clinically and radiologically stable over 3 years of follow-up (Fig. 6).

Fig. 6. Canine showed clinically and radiologically stable for (A and B) 1 years, (C and D) 2 years, and (E and F) 3 years follow-up.

The overall outcomes are summarized in Table 1. In both cases, all investigated periodontal clinical parameters improved significantly and remained stable during the 3-year postoperative observation period (Table 1). In terms of pocket probing depth (PPD), both cases showed a decrease of 4 mm and 1 mm, respectively, and this was maintained until 3 years of follow-up. In terms of the REC, both cases showed a decrease. In case 1, it was improved from 4.5 mm to 2.5 mm, and an additional 0.5 mm was improved from 2 years to 3 years of follow-up. In case 2, the improvement in REC was from 7 mm to 5 mm, and an additional 0.5 mm was improved at 2 years of follow-up. Both cases resolved in terms of bleeding on probing and mobility.

This case report showed favorable and stable long-term results of periodontal regenerative treatment using enamel matrix derivative (EMD) and bone grafting materials accompanied with CTG and EMD in the maxillary canine where REC and intrabony defects were present.

Periodontal regenerative treatment using a variety of regenerative materials, including resorbable and non-resorbable barrier membranes, bone replacement grafts, active biological agents, and combinations of these, has demonstrated a more significant clinical and radiographic improvement than OFD alone in intrabony defects [1]. In recent years, to reduce postoperative complications, such as wound dehiscence with subsequent inflammation and infection, caused by barrier membrane exposure, a regenerative technique without the use of a barrier membrane has been introduced, and its usefulness and efficacy have been demonstrated in several short- and long-term clinical studies [9-12].

To date, positive results have been obtained after using CAF alone and CAF with CTG for treating local REC [13]. A systematic review reported that a greater amount of root coverage was achieved in local REC with CAF in combination with CTG than with CAF alone. Another systematic review and meta-analysis also confirmed that the short-and long-term stability of CAF in combination with CTG was better than that of CAF alone for REC of a single tooth, involving an increase in the thickness of the gingiva [14,15]. In this study, both cases showed stable outcomes for 3 years, where decreased PPD after treatment was maintained and REC improved steadily. Additionally, the width of keratinized tissue was significantly improved and more stable in CAF in combination with CTG than in CAF alone [14]. Unfortunately, the width of the keratinized gingiva was not measured and improvement was not evaluated in our study.

The gradual coronal movement of gingival margin levels observed at sites treated with CAF in combination with CTG can be attributed to creeping attachment and tissue maturation, which is significantly facilitated by thick gingiva formed after CTG [13]. A long-term clinical study by Rasperini et al. [13] reported that the estimated coronal shift of CAF with CTG and CAF alone was 0.009 mm and 0.017 mm per year, respectively. We obtained coincidence findings in our two cases wherein postoperative gingival margins moved slightly coronal 0.5 mm during a 3-year follow-up.

Various types of bone grafting materials with the adjunctive use of EMD have shown significantly improved clinical and radiographic outcomes [16]. The use of EMD, consisting of amelogenin and other related proteins, including enamelin, ameloblastin, and amelotin, from porcine fetal teeth, has shown significant clinical improvement in PPD reduction, CAL increase, and bone formation in several recent clinical studies [17]. Furthermore, OFD with adjunctive use of EMD and grafting materials showed better results in CAL gain, PPD reduction, and bone gain compared to OFD and EMD only [16]. Additionally, since EMD has demonstrated soft tissue regeneration and angiogenic activity and plays an important role in wound healing, combining EMD with CTG can have a positive effect on periodontal wound healing, keratinization process, and root coverage, which also further improves clinical outcomes [18-20]. In a 3-year randomized clinical trial, CTG with adjunctive use of EMD showed significantly lower REC and higher keratinized tissue width than CTG without EMD [21].

This case report showed favorable resolution of both intrabony defects and REC by periodontal regenerative treatment with CTG and EMD. A similar retrospective study by Trombelli et al. [22] was performed earlier to investigate whether CTG prevented postoperative REC after regenerative surgery of intrabony defect. Intraosseous defect was filled with EMD and bone graft after minimal flap elevation, and increased REC was compared between groups with and without adjunctive use of CTG. After 6 months, the CTG group showed a lower increase in REC. The difference between our cases is that REC decreased in this study and increased in the above study, which might be due to the amount of flap elevation and surgical techniques.

Regardless of whether non-carious cervical lesions were repaired, CAF with or without CTG showed decreased REC and increased CAL. At 6 months after surgery, REC, CAL, and esthetics did not affect restoration status, but CTG showed better outcomes [23,24]. In this study, in the first patient, the cervical restoration beyond the cemento-enamel junction (CEJ) was removed and the flap margin was placed up to the anatomical CEJ; however, in the second patient, the restoration was placed beyond the CEJ and the flap margin was placed below the restoration. The difference in the amount of change in CAL may be because of this difference.

The major risk factors for increasing REC are thin buccal bone morphology and a thin gingival biotype. In particular, the anatomical form is closely related to the maxillary anterior region [25,26]. The average thickness of the buccal bone and soft tissue of the maxillary anterior region is <1 mm, with the lowest thickness in the canines [27]. Specifically, cone-beam computerized tomography and ultrasonic measuring device-based studies reported that the average gingival thickness of maxillary anterior canine is 0.2 mm and 0.7 mm, respectively [28,29]. Therefore, in this study, we report on the treatment of maxillary canines where intrabony defects and REC can easily appear. However, there is a limitation of comparing only two cases by retrospective case selection. In addition, only the change in the coronally apical direction of the gingiva was compared, and there was a limitation in not being able to compare the thickness recording.

According to several previous studies, periodontal regenerative surgery is widely used as one of the most predictive treatment modalities for intrabony defects, and CAF with subepithelial CTG can also be used to resolve moderate-to-severe REC. Additionally, the use of EMD will further improve the clinical outcomes. However, there is still controversy over how the combination of treatment techniques is better than other techniques. With appropriate case selection and corresponding treatment, periodontal regenerative treatment in combination with CTG may be considered as one of the predictive treatment methods for deep intrabony defects and REC in the maxillary canine.

This work was supported by Wonkwang University in 2021.

The authors declare that they have no competing interests.